What Graduate Degree is Right for Me?

Question: Hello! I am very interested in theoretical physics, planetary science, and engineering. What graduate degree is right for me?  — Cole

Answer: Most professional physicists and astronomers have doctorate (PhD) degrees.  As for which doctorate program to pursue with your interests in theoretical physics, planetary science, and engineering, I suspect that a graduate program that specializes in planetary science would cover all of them.  With a focus on planetary science you could pursue both theoretical and instrumentation (engineering) projects.

Jeff Mangum

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What Happens to the Other Planets in the Solar System if Jupiter is Removed?

Question: What would happen to the other planets in the solar system if we removed Jupiter?  — Willie

Answer: Instantaneously removing Jupiter from the solar system would have little effect on Earth and the other planets.  This is due to the fact that Jupiter is about 1/1000th the mass of the Sun, and it is about 5 times further away from us than the Sun.  Since the gravitational force on a planet of mass M due to an object of mass m and distance R is given by F=GMm/(R^2) (this is Newton’s Law), the effect of Jupiter on the Earth is 1/25000 that of the effect of the Sun on Earth.  This effect is negligibly small.  Now, Jupiter’s removal would have a big effect on its moons and the asteroids which inhabit the asteroid belt since Jupiter’s mass has a big effect on their orbits.

Jeff Mangum

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Spacecraft Launched in the 1970s Which Were Inscribed with Names?

Question: My dad has always told me about how his name is floating out in space on some spacecraft. Now he would like to see a copy of the list of names on that spacecraft but he can’t remember the name of it. He knows that he went to Langley airfield in the 1970s and got his name on what he is calling a microdot. He said he thinks that the aircraft is still in space and may be the one that is furthest out. However, I thought that the Voyager was the furtherest object and everything I’ve read about the Voyager says that it does not have public names on it. Could you help me find what he is talking about please?  — Melissa

Answer: I am sorry but I was not able to find any information about names inscribed on spacecraft launched in the 1970s.  About the only suggestion I can make is the check the Wikipedia list of artificial satellites and space probes and see if any of those launched in the 1970s might match what you are looking for.

Jeff Mangum

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Interested in a Career as an Astronomer

Question: Hey! I’m Tina and I’m from Sri Lanka. I’m 16 years old. I want to be an astronomer. I’m really interested in the universe and how it started to be this wonderful. What kind of educational requirements should I have to become an astronomer?  — Tina

Answer: Great to hear that you are interested in pursuing a career in science!  For information on a career path to becoming an astronomer, take a look at the posts in our Careers in Astronomy section of this blog.  If you have further questions after looking over this information, let me know.

Jeff Mangum

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How Does a Single Dish Telescope Make Images?

Question: How does a single-dish telescope, such as Green Bank, produce images–at least images of more than one pixel? By physically steering the telescope to aim at slightly different patches of the sky?  — Kent

Answer: You have it right!  Images are made with the Green Bank Telescope by moving the antenna to point at different positions on the sky, then stitching those measurements together to make an image.  Some of the detectors on the Green Bank Telescope have multiple pixels, which makes this mapping process quite a bit faster since you can cover a larger patch of sky with each pointing.

Jeff Mangum

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Will a Comet Skim the Earth’s Atmosphere in 2016?

Question: I’ve been dealing with a false prophet who says that a comet is coming and is going to skim the earth, as if to skip off of it, like a stone skipping on water.  Is this even possible?  She says it will skip off of the earth and keep going into space.  Please let me know if this is even possible?  Thanks so much.  — Andrew

Answer: The scenario you describe is physically possible, but the actual event described by this “false prophet” is misrepresented.  A pair of comets, known as 252P/LINEAR and P/2016 BA14, passed close to Earth on March 21 and 22, 2016.  The closest that they came was within 2.2 million miles of the Earth, or about 9.6 times the distance between the Earth and the Moon.  Comets have on a couple of occasions passed closer to Earth, and as was the case with the most recent comet passage we survived.

Jeff Mangum

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Requirements for a Career in Astronomy

Question: hi there. My name is Calvin, And I’m a twelve year old boy. I’d love to join the astronomers. I just have 1 question. What is required to get a job there and is this job a challenge?  — Calvin

Answer: Great to hear that you are interested in pursuing a career in astronomy Calvin.  You can find quite a bit of information about what is required to pursue a career in astronomy by reading the questions and answers posted to the Careers in Astronomy section of this blog.  If you have further questions after looking over this information let me know.

Jeff Mangum

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A Question About Changing Careers to Astronomy

Question: I am Viraj Mulay,24 from India. I am very passionate about astronomy and the related topics like stars,planets,milkyway,blackholes,etc since childhood. Unfortunately i could not pursuing career in astronomy. I am currently working in finance department and not satisfied with my current work profile. Kindly guide me shall i pursue astronomy as hobby or still i can switch it as my profession.  — Viraj

Answer: You should take a look at the Careers in Astronomy section of this blog for past questions and answers regarding a career in astronomy.  Your situation is not unusual, so I believe that you can find some useful information in our careers section.

Jeff Mangum

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How Do You Distinguish Between People-Made Signals and Those From Space?

Question: You have loads of terrestrial interference, so how do you know the signals you receive are extra terrestrial? — Ariane

Answer: The radio signals that we generate ourselves, such as by radar or radio communications, have a specific frequency and frequency width that we can measure very accurately.  Signals which come from astronomical objects are much weaker, come from a specific direction in the sky, and often have a spectral shape which is very different from those that we measure from astronomical objects.

Jeff Mangum

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Double Shadow Transits of the Galilean Satellites of Jupiter

Question: Why is there a double shadow transit (i.e. of the Galilean moons) season for Jupiter and why does it occur during the opposition of the Jupiter relative to Earth?  Do DST occur all the time, but during opposition, it is more apparent to us on Earth?  — Grace

Answer: Double Shadow Transits (DST), or the shadow of two Galilean satellites on the cloud tops of Jupiter, occur during Jupiter opposition due to the relative alignment of the Sun, Earth, and Jupiter during opposition.  Jupiter opposition makes these events visible to us on Earth, but in fact Galilean shadow events can occur any time that a Galilean satellite passes between Jupiter and the Sun as viewed along a line connecting the Sun and Jupiter.

Jeff Mangum

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